Field of the Invention
The present invention relates to a field device.
Priority is claimed on Japanese Patent Application No. 2015-236596, filed Dec. 3, 2015, the content of which is incorporated herein by reference.
Description of Related Art
All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains.
In a plant including various facilities, a plurality of field instruments (measuring instruments or actuators) which are called field devices are installed for the purpose of monitoring an operating status of each facility disposed in the plant or controlling operations of the facilities. In such a plant, a checking operation of routinely or periodically checking operations of field devices is performed in order to maintain soundness of the field devices, that is, to enable the field devices to accurately detect the operating statuses of facilities.
Conventionally, when a field device is checked, a method of having an operator perform a checking operation of moving to a place in which the field device is installed with a paper maintenance log on which to write items, details, or the like to be checked and checking a display of a display unit of the field device based on the maintenance log is used. At this time, so-called calibration of connecting a reference signal generator or the like outputting a reference output signal instead of a sensor of the field device to the field device and checking or adjusting the field device based on the output signal output from the connected reference signal generator may be performed.
Recently, for example, like a technique disclosed in Japanese Patent No. 5574191, an operation verifying system that verifies soundness of a field device using an operation verifying tool has been proposed. In the technique disclosed in Japanese Patent No. 5574191, parameters or data output from the field device to the device checking terminal are acquired, for example, by connecting a device checking terminal executing the operation verifying tool to the field device and performing communication in a communication standard that the field device supports. The device checking terminal verifies the soundness of the field device by performing a process of comparing the acquired parameters or data with a predetermined determination criterion. Accordingly, in the technique disclosed in Japanese Patent No. 5574191, the soundness of the field device can be verified in real time.
In order to verify soundness of a field device, many parameters or a large amount of data is required for each item to be verified. Accordingly, in the technique disclosed in Japanese Patent No. 5574191, many parameters or a large amount of data output from the field device is input to the device checking terminal to verify the soundness of the field device. However, since the communication of the communication standard that a field device supports employs a communication mode of transmitting data using a communication signal which is superimposed on the output signal of the field device, a communication speed for exchanging (transmitting) the parameters or data is low. Accordingly, in verification of the soundness of the field device using the technique disclosed in Japanese Patent No. 5574191, much time is required to acquire the many parameters or large amount of data from the field device and much time is required until the device checking terminal completes the verification of the soundness of the field device. That is, in the related art, the checking operation of verifying soundness of a field device has poor efficiency.